Ramachandran Pravena, Lee Chong Yew, Doong Ruey-An, Oon Chern Ein, Kim Thanh Nguyen Thi, Lee Hooi Ling
Nanomaterials Research Group, School of Chemical Sciences, Universiti Sains Malaysia 11800 USM Penang Malaysia
School of Pharmaceutical Sciences, Universiti Sains Malaysia 11800 USM Penang Malaysia.
RSC Adv. 2020 Jun 10;10(37):21795-21805. doi: 10.1039/d0ra02907f. eCollection 2020 Jun 8.
Titanium dioxide nanoparticles (TiO NPs) have attracted tremendous interest owing to their unique physicochemical properties. However, the cytotoxic effect of TiO NPs remains an obstacle for their wide-scale applications, particularly in drug delivery systems and cancer therapies. In this study, the more biocompatible nitrogen-doped graphene quantum dots (N-GQDs) were successfully incorporated onto the surface of the TiO NPs resulting in a N-GQDs/TiO nanocomposites (NCs). The effects of the nanocomposite on the viability of the breast cancer cell line (MDA-MB-231) was evaluated. The N-GQDs and N-GQDs/TiO NCs were synthesised using a one- and two-pot hydrothermal method, respectively while the TiO NPs were fabricated using microwave-assisted synthesis in the aqueous phase. The synthesised compounds were characterised using Fourier transform infrared (FTIR) spectroscopy, high-resolution transmission electron microscopy (HRTEM), field emission scanning electron microscopy (FESEM) and UV-visible spectrophotometry. The cell viability of the MDA-MB-231 cell line was determined using a CellTiter 96® AQueous One Solution Cell Proliferation (MTS) assay. The obtained results indicated that a monodispersed solution of N-GQDs with particle size 4.40 ± 1.5 nm emitted intense blue luminescence in aqueous media. The HRTEM images clearly showed that the TiO particles (11.46 ± 2.8 nm) are square shaped. Meanwhile, TiO particles were located on the 2D graphene nanosheet surface in N-GQDs/TiO NCs (9.16 ± 2.4 nm). N-GQDs and N-GQDs/TiO NCs were not toxic to the breast cancer cells at 0.1 mg mL and below. At higher concentrations (0.5 and 1 mg mL), the nanocomposite was significantly less cytotoxic compared to the pristine TiO. In conclusion, this nanocomposite with reduced cytotoxicity warrants further exploration as a new TiO-based nanomaterial for biomedical applications, especially as an anti-cancer strategy.
二氧化钛纳米颗粒（TiO NPs）因其独特的物理化学性质而引起了极大的关注。然而，TiO NPs的细胞毒性作用仍然是其大规模应用的障碍，特别是在药物递送系统和癌症治疗中。在本研究中，更具生物相容性的氮掺杂石墨烯量子点（N-GQDs）成功地掺入到TiO NPs表面，形成了N-GQDs/TiO纳米复合材料（NCs）。评估了该纳米复合材料对乳腺癌细胞系（MDA-MB-231）活力的影响。N-GQDs和N-GQDs/TiO NCs分别采用一锅法和两锅法水热合成，而TiO NPs则采用水相微波辅助合成制备。使用傅里叶变换红外（FTIR）光谱、高分辨率透射电子显微镜（HRTEM）、场发射扫描电子显微镜（FESEM）和紫外可见分光光度法对合成的化合物进行了表征。使用CellTiter 96® AQueous One Solution Cell Proliferation（MTS）测定法测定MDA-MB-231细胞系的细胞活力。所得结果表明，粒径为4.40±1.5 nm的N-GQDs单分散溶液在水性介质中发出强烈的蓝色荧光。HRTEM图像清楚地表明，TiO颗粒（11.46±2.8 nm）呈方形。同时，在N-GQDs/TiO NCs（9.16±2.4 nm）中，TiO颗粒位于二维石墨烯纳米片表面。在0.1 mg/mL及以下浓度时，N-GQDs和N-GQDs/TiO NCs对乳腺癌细胞无毒。在较高浓度（0.5和1 mg/mL）下，与原始TiO相比，该纳米复合材料的细胞毒性明显较低。总之，这种具有降低细胞毒性的纳米复合材料作为一种新型的基于TiO的纳米材料在生物医学应用中，特别是作为一种抗癌策略，值得进一步探索。
